From 5f40555b99ca65fca808c6546f0af34d9caa53bc Mon Sep 17 00:00:00 2001 From: Tomasz Jozwiak Date: Mon, 14 Jan 2019 16:11:21 +0100 Subject: [PATCH] doc: update qat compression guide Added limitations description for the QAT compression PMD. Updated intermediate buffers description in qat.rst file. Signed-off-by: Tomasz Jozwiak Acked-by: Fiona Trahe --- doc/guides/compressdevs/qat_comp.rst | 4 ++++ doc/guides/cryptodevs/qat.rst | 6 ++++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/doc/guides/compressdevs/qat_comp.rst b/doc/guides/compressdevs/qat_comp.rst index 567a1fc806..5631cb15af 100644 --- a/doc/guides/compressdevs/qat_comp.rst +++ b/doc/guides/compressdevs/qat_comp.rst @@ -35,6 +35,10 @@ Limitations * Compressdev level 0, no compression, is not supported. * Queue pairs are not thread-safe (that is, within a single queue pair, RX and TX from different lcores is not supported). * No BSD support as BSD QAT kernel driver not available. +* Number of segments in mbuf chains in the op must be <= RTE_PMD_QAT_COMP_SGL_MAX_SEGMENTS from the config file. +* When using Deflate dynamic huffman encoding for compression, the input size (op.src.length) + must be < CONFIG_RTE_PMD_QAT_COMP_IM_BUFFER_SIZE from the config file, + see :ref:`building_qat_config` for more details. Installation diff --git a/doc/guides/cryptodevs/qat.rst b/doc/guides/cryptodevs/qat.rst index 3ca70bc05c..b079aa381c 100644 --- a/doc/guides/cryptodevs/qat.rst +++ b/doc/guides/cryptodevs/qat.rst @@ -144,6 +144,8 @@ Quick instructions for QAT compressdev PMD are as follows: make +.. _building_qat_config: + Build Configuration ~~~~~~~~~~~~~~~~~~~ @@ -179,8 +181,8 @@ An extra (max_inflight_ops x 16) bytes per queue_pair will be used for every inc QAT compression PMD needs intermediate buffers to support Deflate compression with Dynamic Huffman encoding. CONFIG_RTE_PMD_QAT_COMP_IM_BUFFER_SIZE specifies the size of a single buffer, the PMD will allocate a multiple of these, -plus some extra space for associated meta-data. For GEN2 devices, 20 buffers plus -1472 bytes are allocated. +plus some extra space for associated meta-data. For GEN2 devices, 20 buffers are +allocated while for GEN1 devices, 12 buffers are allocated, plus 1472 bytes overhead. .. Note:: -- 2.20.1